Mission 20

Mission 20: Screaming Souls

Use the Swordmaster style, or your favorite/preferred style if you have one, and enter the stage. Try bringing three Vital Star Ls, 1 Holy Water, and 2 Devil Stars. Use Ebony & Ivory from the very start of the battle, as Vergil is too fast for Kalina Ann. Vergil is more powerful than the previous battles, which is what you would expect from a last boss in any game, much less one as hard as this one. The thing about defeating him is that he's pretty much identical to his previous form that you faced, only this time he will Devil Trigger entirely too much, and he has extremely fast teleportation skills. After he Devil Triggers, which you should run away from immediately, Devil Trigger yourself to take down a chunk of his health bar with a Devil Trigger combo.

At around halfway to death, Vergil will Sparda Trigger, turning him into a blue inferno of unpleasantness. During this time period, Devil Trigger yourself to gain extra speed and use this time to run like hell! Just run around to escape Sparda Triggered Vergil, and return to him to get a few cheap hits in when he returns to normal state. Vergil will also Devil Trigger a lot faster when nearing death (around 25% or so of health points left), making things a lot harder since you cannot Devil Trigger on time every time anymore. Get close to him and use the Holy Water to finish him off.

Congratulations! You have completed one of the hardest games on the PlayStation 2, Devil May Cry 3! Now go celebrate by playing some Pong.